| Turbo-Thrift | |
|---|---|
.jpg) | |
| Overview | |
| Manufacturer | Chevrolet |
| Production | 1962–1988 1964–2001 (Brazil) 1964–1999 (South Africa) 1962–2001 (Argentina) |
| Layout | |
| Displacement | 194 cu in (3.2 L) 230 cu in (3.8 L) 250 cu in (4.1 L) 292 cu in (4.8 L) |
| Cylinder bore | 3+9⁄16 in (90.5 mm) 3+7⁄8 in (98.4 mm) |
| Piston stroke | 3+1⁄4 in (82.6 mm) 3.53 in (89.7 mm) 4+1⁄8 in (104.8 mm) |
| Cylinder block material | Cast iron |
| Cylinder head material | Cast iron |
| Valvetrain | OHV 2 valves per cyl. |
| Combustion | |
| Fuel system | Rochester one barrelCarburetor Multi-port fuel injection |
| Fuel type | Gasoline |
| Oil system | Wet sump |
| Cooling system | Water-cooled |
| Dimensions | |
| Length | 32.5 in (830 mm) |
| Chronology | |
| Predecessor | Chevrolet Blue Flame |
| Successor | Chevrolet 90° V6 engine |
TheChevrolet Turbo-Thrift engine is astraight-six produced from 1962 to 2001 by theChevrolet division ofGeneral Motors. The entire series of engines was commonly calledTurbo-Thrift, although the name was first used on the 230 cubic inch version that debuted in 1963.[1] The new engine featured seven main bearings in lieu of the four bearing design of its predecessor, the "Stovebolt" engine, and was considerably smaller and approximately 100 lbs lighter.[2]
There were other major differences between the Turbo-Thrift engine and the Stovebolt:
The first use of the new engine series was the 194 cu in (3.2 L)Hi-Thrift version in the 1962Chevy II; the following year, Chevrolet passenger cars adopted the 230 cu in (3.8 L) version across the range.Studebaker andChecker also began using the engine in 1965.[3]: 341 Chevrolet and GMC trucks, which previously used the Stovebolt andGMC V6 engines, also switched to using the Turbo-Thrift from 1963 through 1988, as didPontiac in 1964 and 1965. A 153-cubic-inch (2.5 L)inline-4 version of this engine was also offered in the Chevy II/Nova line through the 1970 model year.
After several years of steadily declining sales (just 3,900 units in the 1972model year),[3]: 881 the straight-six was dropped from Chevrolet's full-sized cars for 1973, the first time the full-sized Chevrolet had not been available with a six-cylinder since 1928. However, when theB-body line wasdownsized in 1977, the engine was reintroduced.[3]: 881 The base six cost about US$334 less than a V8, and weighed some 188 lb (85 kg) less.[3]: 881
Overseas, the engine was also mass-produced inBrazil. It was used in theChevrolet Opala from 1969 (230) to 1992 (250). It was also used in light trucks, including theChevrolet Veraneio. The Brazilian version of theGMT400 – the Brazilian Chevrolet Silverado – is powered with a 4.1 instead of theVortec 4300 V6. Brazilian-produced sixes manufactured to the 2001 model year gained multipoint fuel injection, unlike the US-manufactured sixes, which retained theRochester Monojet one-barrel carburetor. These inline-sixes and theirfour-cylinder siblings were converted for marine usage byMercruiser andVolvo Penta, and also used in stationary applications (such as power generation) and in Clarkforklifts.[4] Aftermarket port fuel injection and re-engineered cylinder heads have been the norm, although parts for the inline-six, such as aftermarket intake manifolds (from a three-carburetor setup or a single 4-barrel carburetor), exhaust headers, and hybrid cylinder heads based on Chevrolet'ssmall-block engine are costlier than those for thesmall-block, unlike the rivalAMC inline-six (which has a cult following with Jeep enthusiasts, especially with the 4.0 L). Chevrolet's inline-six engine was also manufactured in Argentina and South Africa.
TheHi-Thrift 194 was introduced as the optional engine in the 1962Chevy II. Bore and stroke are3+9⁄16 in × 3+1⁄4 in (90 mm × 83 mm), for a total displacement of 194 cu in (3,185 cc).[5] It was also optional in the 1964G10 Chevy Van1⁄2-ton vans, and standard in the G10 in 1965 and 1966; it was not available in the C/K101⁄2-ton trucks.[6] The engine produced peak power of 120 hp (89 kW) (gross) and 177 lb⋅ft (240 N⋅m) of torque.[7]
The 194 variant ended production in North America after 1967, but remained in use byGeneral Motors' Argentinian subsidiary until the mid-1970s. GM de Argentina also developed a 109.7 cu in (1,797 cc) four-cylinder version called the "Chevrolet 110" for theirOpel K 180 compact car.[8]
Pontiac's 215 cu in (3.5 L) (1964–1965) was a smaller bore of 3.75 in (95.25 mm) version of the 230 cu in (3.8 L) Chevrolet straight-six engine. One oddity is the crankshaft bolt pattern; in lieu of the Chevrolet V8 bolt pattern (also shared with the rest of the third-generation six), thePontiac V8 bolt pattern is used.
TheTurbo-Thrift 230 (also known as theHigh Torque 230 in Chevrolet trucks), with 230 cu in (3,768 cc) displacement, replaced the long-stroke235 cu in (3.9 L) version of the Stovebolt six beginning in 1963. Bore and stroke were3+7⁄8 in × 3+1⁄4 in (98 mm × 83 mm). It was also used by Chevrolet and GMC trucks, primarily for the half-tons. It produced a peak 140 hp (104 kW) at 4,400 rpm and 220 lb⋅ft (298 N⋅m) at 1,600 rpm. North American production of this variant ceased in 1970. It was also built in Latin America and was in production in South Africa until at least 1982, where it powered a multitude of different cars. A four-cylinder version of this engine was also built, theSuper-Thrift 153.
TheTurbo-Thrift 250 (also known as theHigh Torque 250 in trucks) version was introduced in 1966, with the same 3.875 in (98.4 mm) bore as the230 and a longer 3.53 in (90 mm) stroke for a larger 249.8 cu in (4.1 L; 4,093 cc) displacement. Between 1975 and 1984, an integrated cylinder head was produced (intake manifold and cylinder head were a single casting with a bolt on exhaust manifold). One-barrel intakes were used in passenger cars and trucks through 1978. Starting in 1979, a two-barrel intake fitted with a Rochester Varajet carburetor and dual take down exhaust manifold were used in trucks and vans. The "integrated" cylinder head and intake manifold claimed to have resulted in increased low end torque and fuel economy inclusive of a smoother operation, lowering NVH (noise, vibration, and harshness).
The engine was sold in various states of tune and under several differentRPO codes over its production life. The L22 was the passenger car version, sold until 1979. The LD4 was the truck version, sold until 1978. The LE3 replaced the LD4 in 1979 and was produced until 1984.
In the late 1970s, theChevrolet 200,Chevrolet 229 andBuick 231V6 engines gradually replaced the 250 straight six in passenger cars in North America, with use of the engine discontinued after the 1979 model year. The 250 engine continued to be used in GM trucks until 1984, after which it was replaced by the4.3 L V6 (essentially a350-cubic-inch (5.7 L) Chevy small-block V8 with the two rear cylinders removed). It was also used in a number of large sedans by Chevrolet of South Africa until 1982.
Production continued in Brazil (known as the 4.1 there) until 1998 in passenger cars, when theChevrolet Omega A was replaced by rebadged AustralianHoldens. It was used until 2001 in the BrazilianChevrolet Silverado, after which the engine line was discontinued. Latter-day Brazilian-produced engines featured electronic multipoint fuel injection, distributorless ignition system and redesigned cylinder heads with smaller intake ports.
GM did not produce another straight-six engine in North America until the introduction of theGM Atlas engine in late 2001.
| Year | Compression Ratio | Power[A] | Torque[A] | Notes | Reference |
|---|---|---|---|---|---|
| 1966–1970 | 8.5:1 | 155 hp (116 kW) @ 4200 rpm | 235 lb⋅ft (319 N⋅m) @ 1600 rpm | [12][15][16][19][20] [21][22][23][17][24] [25][26][27][28][29] | |
| 1971 | 145 hp (108 kW) @ 4200 rpm | 230 lb⋅ft (312 N⋅m) @ 1600 rpm | [30][31] | ||
| 1972 | 110 hp (82 kW) @ 3800 rpm | 185 lb⋅ft (251 N⋅m) @ 1600 rpm | [32][33] | ||
| 1973–1974 | 8.25:1 | 100 hp (75 kW) @ 3600 rpm | 175 lb⋅ft (237 N⋅m) @ 1600 rpm | [34][35][36][37][38] | |
| 1975–1976 | 105 hp (78 kW) @ 3800 rpm | 185 lb⋅ft (251 N⋅m) @ 1200 rpm | "Integrated" cylinder head introduced | [39][40][41][42] | |
| 1977 | 8.3:1 | 110 hp (82 kW) @ 3800 rpm | 195 lb⋅ft (264 N⋅m) @ 1600 rpm | L22, Federal emissions; LD4, light-duty emissions | [43][44] |
| 90 hp (67 kW) @ 3600 rpm | 180 lb⋅ft (244 N⋅m) @ 1600 rpm | L22, California emissions | |||
| 8.0:1 | 100 hp (75 kW) @ 3600 rpm | 175 lb⋅ft (237 N⋅m) @ 1800 rpm | LD4, heavy-duty emissions | ||
| 1978 | 8.1:1 | 110 hp (82 kW) @ 3800 rpm | 190 lb⋅ft (258 N⋅m) @ 1600 rpm | L22, Federal emissions | [45][46] |
| 90 hp (67 kW) @ 3600 rpm | 175 lb⋅ft (237 N⋅m) @ 1600 rpm | L22, California emissions | |||
| 100 hp (75 kW) @ 3800 rpm | 185 lb⋅ft (251 N⋅m) @ 1600 rpm | LD4, light/medium-duty California emissions | |||
| 8.0:1 | 115 hp (86 kW) @ 3800 rpm | 195 lb⋅ft (264 N⋅m) @ 1600 rpm | LD4, light-duty Federal emissions | ||
| 100 hp (75 kW) @ 3600 rpm | 175 lb⋅ft (237 N⋅m) @ 1800 rpm | LD4, heavy-duty Federal emissions | |||
| 1979 | 8.0:1 | 115 hp (86 kW) @ 3800 rpm | 200 lb⋅ft (271 N⋅m) @ 1600 rpm | L22, Federal emissions | [47][48] |
| 8.2:1 | 90 hp (67 kW) @ 3600 rpm | 175 lb⋅ft (237 N⋅m) @ 1600 rpm | L22, California emissions | ||
| 8.3:1 | 130 hp (97 kW) @ 4000 rpm | 210 lb⋅ft (285 N⋅m) @ 2000 rpm | LE3, light/medium-duty Federal emissions | ||
| 125 hp (93 kW) @ 4000 rpm | 205 lb⋅ft (278 N⋅m) @ 2000 rpm | LE3, light-duty California emissions; C/K10 trucks and G10 vans only | |||
| 130 hp (97 kW) @ 4000 rpm | 205 lb⋅ft (278 N⋅m) @ 2000 rpm | LE3, light/medium-duty California emissions; C20 trucks and G20/G30 vans only | |||
| 1980 | 130 hp (97 kW) @ 4000 rpm | 210 lb⋅ft (285 N⋅m) @ 2000 rpm | LE3, light-duty Federal emissions | [49] | |
| 125 hp (93 kW) @ 4000 rpm | 205 lb⋅ft (278 N⋅m) @ 2000 rpm | LE3, light-duty California emissions; C/K10 trucks and G10 vans only | |||
| 130 hp (97 kW) @ 4000 rpm | 205 lb⋅ft (278 N⋅m) @ 2000 rpm | LE3, medium-duty California emissions; C20 trucks and G20/G30 vans only | |||
| 1981–1982 | 115 hp (86 kW) @ 3800 rpm | 200 lb⋅ft (271 N⋅m) @ 2000 rpm | LE3, Federal emissions | [50][51] | |
| 105 hp (78 kW) @ 3600 rpm | 195 lb⋅ft (264 N⋅m) @ 1600 rpm | LE3, California emissions | |||
| 1983 | 120 hp (89 kW) @ 4000 rpm | 205 lb⋅ft (278 N⋅m) @ 2000 rpm | LE3, Federal emissions | [52] | |
| 110 hp (82 kW) @ 3600 rpm | 200 lb⋅ft (271 N⋅m) @ 2000 rpm | LE3, California emissions | |||
| 1984 | 115 hp (86 kW) @ 3600 rpm | 200 lb⋅ft (271 N⋅m) @ 2000 rpm | LE3, Federal emissions | [53] | |
| 110 hp (82 kW) @ 3600 rpm | 200 lb⋅ft (271 N⋅m) @ 1600 rpm | LE3, California emissions |
| A power and torque figures in this table areSAE gross until 1971; thereafter, they areSAE net |
When long distance racing restarted in Brazil in 1973, theChevrolet Opala and theFord Maverick were the main contenders. The Maverick's engine was almost one liter larger than the Opala's, however. DriversBob Sharp and Jan Balder, who shared a ride to second place in the "24 Hours of Interlagos" in August of that year in an Opala, pressuredGeneral Motors do Brasil to field a more powerful racing engine.
By coincidence, engine development manager Roberto B. Beccardi had already been working on such a performance engine project out of his own initiative, but had lacked factory support or approval. Thus, in July 1974, GM started to offer the 250-S engine as an option for the Opala 4100. It was slightly different from the version launched two years later: the project engine was similar to the four-cylinder units, did not get a vibration damper, and used the cooling fan from the standard 2500, with four blades instead of six.
The Opala was now much faster than the Maverick GT and Ford did not waste time. It quickly homologated a version with four-barrel carburetor, called "Quadrijet" in Brazil (no relationship to GM's own RochesterQuadrajet), with performance roughly equivalent to the 250.[citation needed]
The 250-S has 171 hp (126 kW) and 229.7 lb⋅ft (311 N⋅m) at 2,400 rpm.
TheHigh Torque 292 engine, displacing 292 cubic inches (4.8 L), was used in Chevrolet and GMC trucks beginning in 1963 andStep-Van/Value-Vans beginning in 1964. It was also the standard engine in theChevy Van/GMC Vandura G20 and G30 from 1975 to 1978. It is differentiated from the 194/230/250 engines by a1+3⁄4 inches (44.5 mm) taller block deck and relocated passenger-side engine mount. Although it had had a larger displacement than its 261-cubic-inch (4.3 L) Stovebolt predecessor it was approximately 2 inches (51 mm) shorter and1⁄4 inch (6.4 mm) lower.[54] Flywheel bolt pattern is the same as the six and V8, with1⁄2 inch (12.7 mm) bolts for the flywheel if produced after the 1966 model year.
Production of the engine was shifted to Mexico in 1980, and later variants of this engine were marketed as theHigh Torque 4.8 L and by itsRPO codeL25. Unlike the later 250 inline 6 that was designed with an integrated cylinder head, the 292 retained the separate intake (with a Rochester Monojet carburetor) and exhaust manifolds as used with the earlier short deck motors (194–250).
Availability of the 4.8 L engine was slowly curtailed from the late 1970s until production ceased entirely in 1989, and it was replaced by the 4.3 L V6. By 1987, it was only available (outside of California) as an option in3⁄4-ton and 1-tonR/V-series trucks, and as the base engine in P20 and P30Step-Vans.
| Year | Compression Ratio | Power[A] | Torque[A] | Notes | Reference |
|---|---|---|---|---|---|
| 1963 | 8.0:1 | 165 hp (123 kW) @ 3800 rpm | 280 lb⋅ft (380 N⋅m) @ 1600 rpm | [13] | |
| 1964–1970 | 170 hp (127 kW) @ 4000 rpm | 275 lb⋅ft (373 N⋅m) @ 1600 rpm | [14][15][20][23] [25][27][29] | ||
| 1971 | 165 hp (123 kW) @ 4000 rpm | 270 lb⋅ft (366 N⋅m) @ 1600 rpm | [31] | ||
| 1972 | 125 hp (93 kW) @ 3600 rpm | 225 lb⋅ft (305 N⋅m) @ 2400 rpm | [33] | ||
| 135 hp (101 kW) @ 3800 rpm | 240 lb⋅ft (325 N⋅m) @ 2000 rpm | CS50, SS50 trucks | |||
| 1973–1978 | 120 hp (89 kW) @ 3600 rpm | 215 lb⋅ft (292 N⋅m) @ 2000 rpm | [35][38][40] [42][44][46] | ||
| 1979–1982 | 7.8:1 | 115 hp (86 kW) @ 3400 rpm | 215 lb⋅ft (292 N⋅m) @ 1600 rpm | [48][49][50][51] | |
| 1983–1986 | 115 hp (86 kW) @ 3600 rpm | 215 lb⋅ft (292 N⋅m) @ 1600 rpm | [52][53][55][56] | ||
| 1987–1989 | 115 hp (86 kW) @ 4000 rpm | 210 lb⋅ft (285 N⋅m) @ 800 rpm | Only available in R/V-series trucks outside California for 1987 and 1988 Also available in P20 and P30 vans | [57][58] |
| A power and torque figures in this table areSAE gross until 1971; thereafter, they areSAE net |
...the 230 inch version that appeared in the full-size 1963 Chevys, finally replacing the venerable 235 incher "Blue Flame" was called Turbo-Thrift, and the family is typically known by that name.